Precast monolithic concrete culvert terminal



Nov. 25, 1941.

I. E. ObENDAHL PRECAS'I' IONOLITHIG CONCRETE CULVERT TERMINAL Filed March 9, 1940 Inventor Jrve E. Odendahl By his Ai'l'or'neys 7 104 Patented Nov. 25, 1941 UNITED STATES PATENT OFFICE PREGAST' MoNoLrrmo CONCRET CULVERT TERMINAL Irve E. ()dendahl, Minneapolis, Minn., assignor to Elk River Concrete Products Company, Elk a River, Minn., a corporation of Minnesota Application March 9, 1940, S erial No. 323,220 I 2 Claims. Chm-16) My invention provides a pr'e-cast monolithic concrete terminal that takes the place of and eliminates the necessity for what is generally known as a culvert end wall. These culvert end Walls are usually built in masonry structures applied at the delivery or receiving ends of culverts, and their function is to prevent washing away of the embankment or filled-in material. Such end-"walls are not an integral part of any portion of a concrete culvert and require considerable manual labor and are relatively exp n s The pre-cast concrete culvert terminal that I have produced involves a tubular anchoring portion and an integrally formed laterally expanded trough-like apron forming portion. The tubular portion forms 'a sectionof the concrete culvert proper and is adapted to be embedded or buried in the embankment so that-it serves as a good anchor for the trough-like portion. The trough-like apron portion is preferably formed to provide a laterally outwardly flaring or expanded bottom and outwardly diverging side wings; which latter outwardlyslope to correspond substantially or closely to the incline of the embankment. I I p This-concrete terminalperforms all of the desired functions of the built inmasonry end wall and has additional advantages, both asto action and use, and as to the cost of production. I

Generally stated, the invention consists of the novel' construction, combination and arrangement of parts hereinafter described and defined ing drawing wherein like characters indicate like parts throughout the several views.

Referring to the drawing:

Fig. 1 is a perspective looking at the improved culvert terminal from the delivery end thereof;

Fig. 2 is a perspective looking at the culvert terminal from one side;

Fig. 3 is a section through an embankment, such as an elevated roadway, and showing the improved culvert terminal applied at both ends of a culvert made up of the customary concrete sections; and

Fig. 4 is a section showing one side of the embankment and showing the culvert terminal in axial section.

The improved culvert terminal includes a tubular anchoring portion 5 and. a flaring fluid distributing trough-like apron portion 6, which parts are cast of concrete and as a monolithic or single element structure. The tubular ani of the cylindrical anchoring section 5.

choring portion 5 has cylindrical interior and exterior surfaces of substantially constant diameter and the trough-like apron portion 6 flares laterally in both horizontal directions from the sides The apron is open at its top and the upper edges I thereof incline downwardly and flare from the top of the tubular portion 5. The inclination of the upper edge section 1 corresponds closely to the inclination of the embankment or wall. The walls will usually be quite uniform in inclination which is dependent upon the angle of repose of the filling or graded embankment. When ;the

v culvert terminal is applied inthe embankment,

is'shown in Figs. 3 and 4, the upper edges 1 of the apron portion will quite closely coincide, with the inclination of the embankment and wall, and hence, there need be little or no projection of the apron.

The complete culvert will include ordinary concrete pipe sections 8, and one or more of the above described culvert terminals. The culvert pipe sections 8 are preferably cylindrical in crosssection tomatch the terminal anchoring section 5. The end of the tubular anchoring portion 5 of the culvert terminal is preferably rabbeted at 9 to adapt it for telescopic connection to the adjacent pipe section. Due to its Very nature this telescopic connection will essentially serve as means for anchoring the tubular anchoring portion against lateral or vertical movement with respect to the joined culvert section 8.

The water flowing through the culvert, when it reaches the flaring apron portion 6, will be very considerably spread out of the relatively flat flaring bottom of the apron, and its velocity will be correspondingly decreased so that the washing action of the-soil of the embankment will be reduced-to a minimum. Alsoywhen water flows into the culvert, it will be first taken into the flaring apron at relatively low velocity and will be directed to the culvert proper where its velocity will not be detrimental.

Preferably, the tubular portion 5 and the trough 6 will be reinforced by an embedded metallic reinforcement, indicated at I0; and this reinforcement should run from the walls of the apron and within the cylindrical wall of the tubular portion 5, thereby not only reinforcing the parts individually, but tying them together.

It is important that the trough and the tubular portion 5 be very rigidly and integrally united because the portion 5, which will be completely embedded in the embankment and well anchored therein, will, to a large extent, be relied upon to support and anchor the apron against forward tipping action even if some of the soil should be washed from under the outer portion of said trough. Of course, any possible remaining tendency of the apron to tip forwardly will be transmitted, through the telescopic joint 9, to the adjacent pipe section 8 which will serve to further anchor the apron against forward tipping action, and this. very effectively due to the relative remoteness of this first culvert joint fronr the heavy apron. I

My improved so-called culvert terminal will prevent erosion by reducing the velocity of the water flowing through the culvert at the outlet end. This is accomplished V by. changing the character of the flow at the outlet end. The water as it leaves the circular culvert is gradually spread out to a relatively thin wide sheet, the cross-sectional area of which is graduallyincreased to bring about this change in velocity. As already indicated, the culvert terminal can be and will be frequently used as an inlet. The apron, being of the wing type, and having inner wall surfaces that merge smoothly into the circular entrance of the tubular anchoring portion is not apt to clog by material that is carried by the water to the inlet. The entrance to the circular opening is, in other words, rounded so as to reduce entrance loss, and this is an important feature in the carrying capacity of the culvert. In fact, in the preferred embodiment illustrated, the open topped apron forms a relatively smooth and substantially unbroken or uninterrupted continuation of the cylindrical anchoring portion 5, and this applies to both the interior and exterior surfaces of the apron.

This improved concrete culvert terminal, as already stated, takes the place of or makes unnecessary the use of the masonry end wall usually employed and it is obvious that this cast concrete structure can be produced at very much less cost than the end wall structures. I Moreover, the improved culvert terminal tends to increase the capacity of the culvert under certain conditions of flow. By increasing the area of the outlet end above that of the circular end withsides which diverge from the circular section to the end section increases the capacity of the culvert over a culvert of the same circular area having a uniform bore throughout. It will be noted that the metallic reinforcement 6 extends throughout the tubular portion and throughout the walls of the trough-like portion of the complete article and reinforces the mono lithic structure throughout its walls. Also, it will be noted by reference particularly to Figs. 1 and 2, that the bottom of the trough or apronforming portion is substantially flat and that the flaring and tapering edge walls curve not only better and more economical.

upwardly but slightly inward so that some of the earth of the embankment will have a downward pressure on the trough or apron. In this improved device the tubular body portion anchors the apron in the overlaying portion of the wall or embankment and it is further assisted in this anchorage by the portion of the wall or embankment that lies over the curved part of the flaring and tapering apron.

By the use of suitable knock-down or collapsible forms the concrete structure can be built In a companion application, filed of even date herewith, I have disclosed and claimed a form or flask for the economical casting of these devices.

It will be understood that the so-called culvert above described is capable of modification as to details of construction and arrangement of parts within the scope of the invention herein disclosed and claimed.

What I claim is:

1 A pre-cast monolithic terminal for culvert comprising a fluid distributing apron adapted to open through and have its edges substantially flush with the sloping side of an embankment, and a tubular anchoring portion adapted to be buried in the embankment to anchor the apron in position, said tubular anchoring portion having cylindrical interior and exterior surfaces of substantially constant diameters, said apron being open at its top and having an outwardly flaring relatively flat bottom and spaced laterally I outwardly diverging sides with outwardly and downwardly sloping upper edges, the said sides and bottom forming relatively smooth and substantially unbroken continuations of the tubular anchoring portion.

2. A pre-cast monolithic terminal for culvert comprising a fluid distributing apron adapted to open through and have its edges substantially flush with the sloping side of an embankment, and a tubular anchoring portion adapted to be buried in the embankment to anchor the apron in position, said tubular anchoring portion hava ing cylindrical interior and exterior surfaces of substantially constant diameters, said apron being open at its top and having an outwardly flaring relatively fiat bottom and spaced laterally outwardly diverging sides with outwardly and downwardly sloping upper edges, the said sides and bottom forming relatively smooth and substantially unbroken continuations of the tubular anchoring portion, and means for anchoring thuextended end of the tubular anchoring portion of the culvert terminal against vertical displacement with respect to an adjacent aligned culvert section. V

IRVE E. ODENDAHL. 

